SWEN II ESTRYDSEN - król Danii o 1047 . Założyciel dynastii Estrydsenidów. Sweyn was born in England,[3] as the son of Norwegian Ulf Jarl and Estrid Svendsdatter, the daughter of king Sweyn I of Denmark and sister of king Canute the Great. Sweyn grew up a military leader, and served under king Anund Jacob of Sweden for a time.[3] He pillaged the Elbe-Weser area in 1040, but was caught by the Archbishop of Hamburg-Bremen, who released him shortly thereafter.[4]

Svend was made jarl under Danish king Harthacnut,[3] and led a campaign for him against Norway, but was beaten by Magnus I of Norway.[4] When Harthacnut died in 1042, Magnus claimed the Danish throne and made Svend his jarl of Jutland.[5] Sweyn fought for Magnus at the Battle of Lyrskov Heath in 1043.[4] Sweyn won great reputation at Lyrskov Heath, and had the Danish nobles crown him king in Viborg in Jutland.[5] He was defeated by Magnus on several occasions, and had to flee to Sweden. Eventually he managed to return and establish a foothold in Scania.[4]

The war between Magnus and Sweyn lasted until 1045, when Magnus' uncle Harald Hardrada returned to Norway from exile. Harald and Sweyn joined forces, and Magnus decided to share the Norwegian throne with Harald.[3] In 1047 Magnus died, having stated on his deathbed that his kingdom would be divided: Harald would get the throne of Norway, while Sweyn would be king of Denmark.[5] Upon hearing of Magnus' death Sweyn said, "Now so help me God, I shall never yield Denmark